Filtered replication does not work when a target document is purged

When a document with an id is deleted and purged, and a replication process tries to create a document with that id, it does not happen. The replication without the filter works. Ruby test script:

require 'rubygems'
require 'couchrest'

1. setup
   server = CouchRest.new("http://localhost:5984")
   a = server.database('a')
   b = server.database('b')
   a.recreate!
   b.recreate!

1. Add a document doc1 to database a and b
   a.save_doc("_id" => 'doc1')
   b_doc1 = b.save_doc("_id" => 'doc1')

1. Delete and purge doc1 from b
   b.delete_doc("_id" => 'doc1', "_rev" => b_doc1['rev'])
   RestClient.post(File.join(b.root, '_purge'), {'doc1' => [b_doc1['rev']]}

   .to_json, :content_type => :json )

1. Add design with filter
   design = a.save_doc("_id" => "_design/temp", "filters" => {"test" => %|function(doc, req){if(['doc1'].indexOf(doc['_id']) >= 0) {return true;}

   {return false;}}|})

1. Replicate and wait for finish
   RestClient.post("http://localhost:5984/_replicate", {:source => a.root, :filter => "temp/test", :target => b.root}.to_json, :content_type => :json)
   sleep(0.01) while JSON.parse(RestClient.get("http://localhost:5984/_active_tasks")).size > 0

abort "oops" unless b.all_docs['total_rows'] == 1

puts "Test successful"